148   u_char* _offset_array;          // byte array keeping backwards offsets

   148   u_char* _offset_array;          // byte array keeping backwards offsets

   149 

   149 

   150   void check_offset(size_t offset, const char* msg) const {

   150   void check_offset(size_t offset, const char* msg) const {

   151     assert(offset <= N_words,

   151     assert(offset <= N_words,

   152            err_msg("%s - "

   152            err_msg("%s - "

   154                    msg, offset, (uint)N_words));

   154                    msg, offset, (uint)N_words));

   155   }

   155   }

   156 

   156 

   157   // Bounds checking accessors:

   157   // Bounds checking accessors:

   158   // For performance these have to devolve to array accesses in product builds.

   158   // For performance these have to devolve to array accesses in product builds.